$C$ $J$ $T$ If: $ CJ = 2x + 7$, $ JT = 6x + 9$, and $ CT = 80$, Find $JT$.
Solution: From the diagram, we can see that the total length of ${CT}$ is the sum of ${CJ}$ and ${JT}$ $ {CJ} + {JT} = {CT}$ Substitute in the expressions that were given for each length: $ {2x + 7} + {6x + 9} = {80}$ Combine like terms: $ 8x + 16 = {80}$ Subtract $16$ from both sides: $ 8x = 64$ Divide both sides by $8$ to find $x$ $ x = 8$ Substitute $8$ for $x$ in the expression that was given for $JT$ $ JT = 6({8}) + 9$ Simplify: $ {JT = 48 + 9}$ Simplify to find ${JT}$ : $ {JT = 57}$